US Patent 7363138 Wheel slip detection and torque management

A method of controlling traction in a vehicle having at least one non-driven wheel speed sensor. Actual vehicle acceleration and a wheel speed difference are detected. At least one of the actual vehicle acceleration and the wheel speed difference is compared to at least one of a predetermined vehicle acceleration and a predetermined wheel speed difference to detect vehicle wheel slip. A wheel torque is reduced in response to detected wheel slip. The foregoing method allows traction control to be installed in many types of vehicles, including vehicles without ABS. More than one type of wheel slip detection can be implemented, and various types of wheel slip can be detected.